Methods for efficient medium access for wake up radios

ABSTRACT

Methods and systems are described for efficient medium access in wake-up radios. In an exemplary embodiment, a wake up frame (WUF) includes fields indicating a wake-up purpose, wake-up scheduling, and a wake-up TX/RX parameter. The wake-up purpose field identifies one of a plurality of predetermined purposes. A STA receives the wake-up frame and determines whether the frame is intended for that STA. If so, the STA responsively performs an action in accordance with the purpose indicated in the purpose field. Purposes that may be indicated in the WIF purpose field may include Listen to Beacon, Uplink Data Transmission, Downlink Data Transmission, and (Re)Association, among others.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a non-provisional filing of, and claimsbenefit under 35 U.S.C. § 119(e) from, the following U.S. ProvisionalPatent Application Ser. Nos. 62/417,140 entitled “Methods for EfficientMedium Access for Wake Up Radios,” filed Nov. 3, 2016; Ser. No.62/501,933 entitled “Methods for Efficient Medium Access for Wake UpRadios,” filed May 5, 2017; and Ser. No. 62/529,923 entitled “Methodsfor Efficient Medium Access for Wake Up Radios,” filed Jul. 7, 2017, allof which are incorporated herein by reference in their entirety.

BACKGROUND Overview of WLAN Systems

A wireless local area network (WLAN) in Infrastructure Basic Service Set(BSS) mode has an Access Point (AP) for the BSS and one or more stations(STAs) associated with the AP. The AP typically has access or interfaceto a Distribution System (DS) or another type of wired/wireless networkthat carries traffic in and out of the BSS. Traffic to STAs thatoriginates from outside the BSS arrives through the AP and is deliveredto the STAs. Traffic originating from STAs to destinations outside theBSS is sent to the AP to be delivered to the respective destinations.Traffic between STAs within the BSS may also be sent through the APwhere the source STA sends traffic to the AP and the AP delivers thetraffic to the destination STA. Such traffic between STAs within a BSSis really peer-to-peer traffic. Such peer-to-peer traffic may also besent directly between the source and destination STAs with a direct linksetup (DLS) using an 802.11e DLS or an 802.11z tunneled DLS (TDLS). AWLAN using an Independent BSS (IBSS) mode has no AP, and/or STAs,communicating directly with each other. This mode of communication isreferred to as an “ad-hoc” mode of communication.

Using the 802.11ac infrastructure mode of operation, the AP may transmita beacon on a fixed channel, usually the primary channel. This channelmay be 20 MHz wide, and is the operating channel of the BSS. Thischannel is also used by the STAs to establish a connection with the AP.The fundamental channel access mechanism in an 802.11 system is CarrierSense Multiple Access with Collision Avoidance (CSMA/CA). In this modeof operation, every STA, including the AP, will sense the primarychannel. If the channel is detected to be busy, the STA backs off. Henceonly one STA may transmit at any given time in a given BSS.

In 802.11n, High Throughput (HT) STAs may also use a 40 MHz wide channelfor communication. This is achieved by combining the primary 20 MHzchannel, with an adjacent 20 MHz channel to form a 40 MHz widecontiguous channel.

In 802.11ac, Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz,80 MHz, and 160 MHz wide channels. The 40 MHz, and 80 MHz, channels areformed by combining contiguous 20 MHz channels similar to 802.11ndescribed above. A160 MHz channel may be formed either by combining 8contiguous 20 MHz channels, or by combining two non-contiguous 80 MHzchannels, this may also be referred to as an 80+80 configuration. Forthe 80+80 configuration, the data, after channel encoding, is passedthrough a segment parser that divides it into two streams. Inverse fastFourier Transform (IFFT) and time domain processing are done on eachstream separately. The streams are then mapped on to the two channels,and the data is transmitted. At the receiver, this mechanism isreversed, and the combined data is sent to the MAC.

Sub 1 GHz modes of operation are supported by 802.11af, and 802.11ah.For these specifications, the channel operating bandwidths, andcarriers, are reduced relative to those used in 802.11n, and 802.11ac.802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV WhiteSpace (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz,and 16 MHz bandwidths using non-TVWS spectrum. A possible use case for802.11ah is support for machine-type communication (MTC) devices in amacro coverage area. MTC devices may have limited capabilities includingonly support for limited bandwidths, but also include a requirement fora very long battery life.

WLAN systems which support multiple channels, and channel widths, suchas 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel which isdesignated as the primary channel. The primary channel may, but notnecessarily, have a bandwidth equal to the largest common operatingbandwidth supported by all STAs in the BSS. The bandwidth of the primarychannel is therefore limited by the STA, of all STAs in operating in aBSS, which supports the smallest bandwidth operating mode. In theexample of 802.11ah, the primary channel may be 1 MHz wide if there areSTAs (e.g. MTC type devices) that only support a 1 MHz mode even if theAP, and other STAs in the BSS, may support a 2 MHz, 4 MHz, 8 MHz, 16MHz, or other channel bandwidth operating modes. All carrier sensing,and NAV settings, depend on the status of the primary channel: if theprimary channel is busy, for example, due to a STA supporting only a 1MHz operating mode is transmitting to the AP, then the entire availablefrequency bands are considered busy even though majority of it staysidle and available.

In the United States, the available frequency bands which may be used by802.11ah are from 902 MHz to 928 MHz. In Korea it is from 917.5 MHz to923.5 MHz; and in Japan, it is from 916.5 MHz to 927.5 MHz. The totalbandwidth available for 802.11ah is 6 MHz to 26 MHz depending on thecountry code.

High Efficiency WLAN Study Group and TGax

The IEEE 802.11™ High Efficiency WLAN (HEW) Study Group (SG) was createdto explore the scope and purpose of a possible, future amendment toenhance the quality of service all users experience for a broad spectrumof wireless users in many usage scenarios including high-densityscenarios in the 2.4 GHz and 5 GHz band. New use cases which supportdense deployments of APs, and STAs, and associated Radio ResourceManagement (RRM) technologies are being considered by the HEW SG.

Potential applications for HEW include emerging usage scenarios such asdata delivery for stadium events, high user density scenarios such astrain stations, or enterprise/retail environments, and also evidence foran increased dependence on video delivery, and wireless services formedical applications.

The IEEE Standard board approved the IEEE 802.11ax Task Group (TG) basedon a Project Authorization Request (PAR) and Criteria for StandardsDevelopment (CSD) developed in the HEW SG.

In TGax standard meetings, several contributions showed that themeasured traffic for a variety of applications has a large likelihoodfor short packets, and there are network applications that may alsogenerate short packets. The applications include the following:

-   -   Virtual office    -   TPC ACK    -   Video streaming ACK    -   Device/Controller (Mice, keyboards, Game controls, etc.)    -   Access—Probe request/response    -   Network selection—probe requests, ANQP    -   Network management—Control frames

Also, many contributions in 802.11ax have proposed the introduction ofMU features that include UL and DL OFDMA and UL and DL MU-MIMO.Designing and defining a mechanism for multiplexing UL random access fordifferent purposes may be considered in the specification.

The Wake Up Receiver (WUR) Study Group

In July 2016, the IEEE 802.11™ Wake Up Radio (WUR) Study Group (SG) wascreated to explore the scope and purpose of a future PHY and MACamendment to provide enhanced low power operations of 802.11 devices.The MAC and PHY amendments may enable operations of a wake-up radio(WUR). A proposed Project Authorization Request (PAR) and Criteria forStandards Development (CSD) documents have been accepted by the WUR SG.

The expected operation bands of the WUR include 2.4 GHz, 5 GHz and maybe extended to Sub 1 GHz. A WUR device operates as a companion radio tothe primary connectivity radio, which is used to transmit regular 802.11packets. WUR transmits packets that carry only control information andhas active receiver power consumptions of less than one milliwatt.Receiving a wake-up packet by the WUR may cause the primary connectivityradio to wake up from sleep. The WUR is expect to have a range that isat least the same as the range of the primary connectivity radiooperating on at least 20 MHz payload bandwidth.

Both AP and non-AP STAs may have WUR as a companion radio. Some usagecases for WUR include: IoT devices; low power operation for smartphones; quick message/incoming call notification scenario; quick statusquery/report, configuration change scenario; and quickemergency/critical event report scenario.

SUMMARY

In an exemplary embodiment, a method is performed by a station (STA)equipped with a wake-up radio (WUR) and a primary connectivity radio(PCR). While the STA is in a sleep state, the STA receives on the WUR awake-up frame (WUF) from an access point (AP), where the wake-up packetincludes a WUF purpose field including a purpose indicator identifyingone of a plurality of predetermined WUF purposes. In response to theWUF, the STA wakes up the PCR and operates the PCR to communicate withthe AP according to the purpose identified by the purpose indicator. Insome embodiments, the plurality of predetermined WUF purposes include atleast Listen to Beacon, Uplink Data Transmission, Downlink DataTransmission, and Association.

In response to a purpose indicator that indicates Listen to Beacon, theSTA may operate the PCR to receiving the beacon from the AP on the PCR.In some embodiments, the PCR is returned to the sleep state afterreceiving the beacon.

In response to a purpose indicator that indicates an uplink datatransmission, the STA may operate the PCR to transmit uplink data fromthe STA to the AP. In some embodiments, the STA does not send anyPS-Poll frame between the waking up of the PCR and the transmission ofthe uplink data.

In some embodiments, in response to a WUF that includes receiveparameters and a purpose indicator that indicates multi-user downlinktransmission, the PCR is operated to use the receive parameters toreceive a downlink packet intended for the STA. The receive parametersmay include a scheduled receive time for the STA.

In some embodiments, a method for waking up an AP for association andthe medium access procedure for an STA and AP using their primaryconnectivity radio (PCRs) after the AP is woken up includes an STA,(e.g., STA1), equipped with a WUR sending a WUF such as a WUReqF todiscover a suitable AP for association, re-association, uplinktransmission, or uplink/downlink transmission.

In some embodiments, a procedure for an STA to wake up another STA forUL/DL/Peer2Peer transmissions and the procedure for medium access forthe STAs to conduct such UL/DL/Peer2Peer transmissions includes an STA,e.g., STA1 (which may be a non-AP STA or AP), equipped with a WURsending a WUF such as a WUReqF to wake up one or more other STAs, e.g.,STA2, e.g., when it has information indicating that STA2 is currently ina sleep state.

In an exemplary embodiment, a wake up frame includes fields indicating awake-up purpose, wake-up scheduling, and a wake-up TX/RX parameter. Thewake-up purpose field includes a purpose indicator that identifies oneof a plurality of predetermined WUF purposes. A STA receives the wake-upframe and determines whether the frame is intended for that STA. The STAmay ignore the wake-up frame if that frame is not intended for itself.If the wake-up frame is intended for the STA, the STA responsivelyperforms an action in accordance with the purpose indicated in thepurpose field. If the purpose is “Rx beacon,” the STA turns on itsprimary connectivity radio (PCR) at the scheduled time and adjustsreceive parameters to receive a beacon and subsequently to return tosleep. If the purpose is “UL data transmission”, the STA turns on itsPCR at the scheduled time and adjusts transmit parameters to transmituplink data without sending a PS-Poll. If the purpose is “DL datatransmission”, the STA turns on its PCR at the scheduled time andadjusts receive parameters to receive downlink data. If the purpose is“association”, the STA turns on its PCR and transmits a probe responseor beacon. Additional and alternative actions performed in response todifferent wake-up purpose indications are further described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a system diagram illustrating an example communicationssystem in which one or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram illustrating an example wirelesstransmit/receive unit (WTRU) that may be used within the communicationssystem illustrated in FIG. 1A according to an embodiment;

FIG. 1C is a system diagram illustrating an example radio access network(RAN) and an example core network (CN) that may be used within thecommunications system illustrated in FIG. 1A according to an embodiment;

FIG. 1D is a system diagram illustrating a further example RAN and afurther example CN that may be used within the communications systemillustrated in FIG. 1A according to an embodiment;

FIG. 2 depicts a design of a wake up request frame (WUReqF), inaccordance with some embodiments.

FIG. 3 depicts a design of a wake up response frame (WURespF), inaccordance with some embodiments.

FIG. 4 illustrates a procedure for code division wake-up transmissions,in accordance with some embodiments.

FIG. 5 illustrates a procedure for sub-channel based wake-uptransmissions, in accordance with some embodiments.

FIG. 6 illustrates a procedure for random access wake-up transmissions,in accordance with some embodiments.

FIG. 7 illustrates a procedure for uplink data without a purposesindication in a wake up packet.

FIG. 8 illustrates a procedure for an uplink data with a purposesindication in a WUP.

FIG. 9 illustrates a procedure for a configuration request without apurposes indication in a WUP.

FIG. 10 illustrates a procedure for a configuration request with apurposes indication in a WUP.

FIG. 11 illustrates single transmission of a WUR packet and a PCRpacket, in accordance with some embodiments.

FIG. 12 illustrates consecutive transmission of a WUR packet and a PCRpacket, in accordance with some embodiments.

FIG. 13 illustrates single transmission of multiple WUR packets and aPCR packet, in accordance with some embodiments.

FIG. 14 illustrates consecutive transmission of multiple WUR packets anda PCR packet, in accordance with some embodiments.

FIG. 15 illustrates single transmission of multiple WUR packets and PCRpackets for multiple STAs, in accordance with some embodiments.

FIG. 16 illustrates consecutive transmission of multiple WUR packets andPCR packets for multiple STAs, in accordance with some embodiments.

FIG. 17 is a schematic block diagram of a STA equipped with a WUR and aPCR.

EXAMPLE NETWORKS FOR IMPLEMENTATION OF THE EMBODIMENTS

FIG. 1A is a diagram illustrating an example communications system 100in which one or more disclosed embodiments may be implemented. Thecommunications system 100 may be a multiple access system that providescontent, such as voice, data, video, messaging, broadcast, etc., tomultiple wireless users. The communications system 100 may enablemultiple wireless users to access such content through the sharing ofsystem resources, including wireless bandwidth. For example, thecommunications systems 100 may employ one or more channel accessmethods, such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tailunique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM(UW-OFDM), resource block-filtered OFDM, filter bank multicarrier(FBMC), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a RAN104/113, a CN 106/115, a public switched telephone network (PSTN) 108,the Internet 110, and other networks 112, though it will be appreciatedthat the disclosed embodiments contemplate any number of WTRUs, basestations, networks, and/or network elements. Each of the WTRUs 102 a,102 b, 102 c, 102 d may be any type of device configured to operateand/or communicate in a wireless environment. By way of example, theWTRUs 102 a, 102 b, 102 c, 102 d, any of which may be referred to as a“station” and/or a “STA”, may be configured to transmit and/or receivewireless signals and may include a user equipment (UE), a mobilestation, a fixed or mobile subscriber unit, a subscription-based unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watchor other wearable, a head-mounted display (HMD), a vehicle, a drone, amedical device and applications (e.g., remote surgery), an industrialdevice and applications (e.g., a robot and/or other wireless devicesoperating in an industrial and/or an automated processing chaincontexts), a consumer electronics device, a device operating oncommercial and/or industrial wireless networks, and the like. Any of theWTRUs 102 a, 102 b, 102 c and 102 d may be interchangeably referred toas a UE.

The communications systems 100 may also include a base station 114 aand/or a base station 114 b. Each of the base stations 114 a, 114 b maybe any type of device configured to wirelessly interface with at leastone of the WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to oneor more communication networks, such as the CN 106/115, the Internet110, and/or the other networks 112. By way of example, the base stations114 a, 114 b may be a base transceiver station (BTS), a Node-B, an eNodeB, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller,an access point (AP), a wireless router, and the like. While the basestations 114 a, 114 b are each depicted as a single element, it will beappreciated that the base stations 114 a, 114 b may include any numberof interconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 104/113, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals on one or morecarrier frequencies, which may be referred to as a cell (not shown).These frequencies may be in licensed spectrum, unlicensed spectrum, or acombination of licensed and unlicensed spectrum. A cell may providecoverage for a wireless service to a specific geographical area that maybe relatively fixed or that may change over time. The cell may furtherbe divided into cell sectors. For example, the cell associated with thebase station 114 a may be divided into three sectors. Thus, in oneembodiment, the base station 114 a may include three transceivers, i.e.,one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and mayutilize multiple transceivers for each sector of the cell. For example,beamforming may be used to transmit and/or receive signals in desiredspatial directions.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet(UV), visible light, etc.). The air interface 116 may be establishedusing any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104/113 and the WTRUs 102 a,102 b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 115/116/117 using wideband CDMA (WCDMA).WCDMA may include communication protocols such as High-Speed PacketAccess (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-SpeedDownlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet Access(HSUPA).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as Evolved UMTS TerrestrialRadio Access (E-UTRA), which may establish the air interface 116 usingLong Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/orLTE-Advanced Pro (LTE-A Pro).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as NR Radio Access, which mayestablish the air interface 116 using New Radio (NR).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement multiple radio access technologies. For example, thebase station 114 a and the WTRUs 102 a, 102 b, 102 c may implement LTEradio access and NR radio access together, for instance using dualconnectivity (DC) principles. Thus, the air interface utilized by WTRUs102 a, 102 b, 102 c may be characterized by multiple types of radioaccess technologies and/or transmissions sent to/from multiple types ofbase stations (e.g., a eNB and a gNB).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.11 (i.e.,Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, an industrialfacility, an air corridor (e.g., for use by drones), a roadway, and thelike. In one embodiment, the base station 114 b and the WTRUs 102 c, 102d may implement a radio technology such as IEEE 802.11 to establish awireless local area network (WLAN). In an embodiment, the base station114 b and the WTRUs 102 c, 102 d may implement a radio technology suchas IEEE 802.15 to establish a wireless personal area network (WPAN). Inyet another embodiment, the base station 114 b and the WTRUs 102 c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. Asshown in FIG. 1A, the base station 114 b may have a direct connection tothe Internet 110. Thus, the base station 114 b may not be required toaccess the Internet 110 via the CN 106/115.

The RAN 104/113 may be in communication with the CN 106/115, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. The data may have varying qualityof service (QoS) requirements, such as differing throughputrequirements, latency requirements, error tolerance requirements,reliability requirements, data throughput requirements, mobilityrequirements, and the like. The CN 106/115 may provide call control,billing services, mobile location-based services, pre-paid calling,Internet connectivity, video distribution, etc., and/or performhigh-level security functions, such as user authentication. Although notshown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or theCN 106/115 may be in direct or indirect communication with other RANsthat employ the same RAT as the RAN 104/113 or a different RAT. Forexample, in addition to being connected to the RAN 104/113, which may beutilizing a NR radio technology, the CN 106/115 may also be incommunication with another RAN (not shown) employing a GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

The CN 106/115 may also serve as a gateway for the WTRUs 102 a, 102 b,102 c, 102 d to access the PSTN 108, the Internet 110, and/or the othernetworks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) and/orthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired and/or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another CN connected to one or more RANs, whichmay employ the same RAT as the RAN 104/113 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities (e.g., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks). For example, the WTRU 102 c shown in FIG. 1A may be configuredto communicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram illustrating an example WTRU 102. As shownin FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120,a transmit/receive element 122, a speaker/microphone 124, a keypad 126,a display/touchpad 128, non-removable memory 130, removable memory 132,a power source 134, a global positioning system (GPS) chipset 136,and/or other peripherals 138, among others. It will be appreciated thatthe WTRU 102 may include any sub-combination of the foregoing elementswhile remaining consistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In an embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and/or receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

Although the transmit/receive element 122 is depicted in FIG. 1B as asingle element, the WTRU 102 may include any number of transmit/receiveelements 122. More specifically, the WTRU 102 may employ MIMOtechnology. Thus, in one embodiment, the WTRU 102 may include two ormore transmit/receive elements 122 (e.g., multiple antennas) fortransmitting and receiving wireless signals over the air interface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as NR and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs and/or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, a Virtual Reality and/or Augmented Reality (VR/AR) device, anactivity tracker, and the like. The peripherals 138 may include one ormore sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientationsensor, a proximity sensor, a temperature sensor, a time sensor; ageolocation sensor; an altimeter, a light sensor, a touch sensor, amagnetometer, a barometer, a gesture sensor, a biometric sensor, and/ora humidity sensor.

The WTRU 102 may include a full duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for both the UL (e.g., for transmission) anddownlink (e.g., for reception) may be concurrent and/or simultaneous.The full duplex radio may include an interference management unit toreduce and or substantially eliminate self-interference via eitherhardware (e.g., a choke) or signal processing via a processor (e.g., aseparate processor (not shown) or via processor 118). In an embodiment,the WRTU 102 may include a half-duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for either the UL (e.g., for transmission) or thedownlink (e.g., for reception)).

FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the CN 106.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and/or receive wireless signals from, the WTRU 102a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the UL and/or DL, and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160 b, 160 c may communicate with one another over an X2 interface.

The CN 106 shown in FIG. 1C may include a mobility management entity(MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN)gateway (or PGW) 166. While each of the foregoing elements are depictedas part of the CN 106, it will be appreciated that any of these elementsmay be owned and/or operated by an entity other than the CN operator.

The MME 162 may be connected to each of the eNode-Bs 162 a, 162 b, 162 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM and/or WCDMA.

The SGW 164 may be connected to each of the eNode Bs 160 a, 160 b, 160 cin the RAN 104 via the S1 interface. The SGW 164 may generally route andforward user data packets to/from the WTRUs 102 a, 102 b, 102 c. The SGW164 may perform other functions, such as anchoring user planes duringinter-eNode B handovers, triggering paging when DL data is available forthe WTRUs 102 a, 102 b, 102 c, managing and storing contexts of theWTRUs 102 a, 102 b, 102 c, and the like.

The SGW 164 may be connected to the PGW 166, which may provide the WTRUs102 a, 102 b, 102 c with access to packet-switched networks, such as theInternet 110, to facilitate communications between the WTRUs 102 a, 102b, 102 c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. Forexample, the CN 106 may provide the WTRUs 102 a, 102 b, 102 c withaccess to circuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. For example, the CN 106 may include,or may communicate with, an IP gateway (e.g., an IP multimedia subsystem(IMS) server) that serves as an interface between the CN 106 and thePSTN 108. In addition, the CN 106 may provide the WTRUs 102 a, 102 b,102 c with access to the other networks 112, which may include otherwired and/or wireless networks that are owned and/or operated by otherservice providers.

Although the WTRU is described in FIGS. 1A-1D as a wireless terminal, itis contemplated that in certain representative embodiments that such aterminal may use (e.g., temporarily or permanently) wired communicationinterfaces with the communication network.

In representative embodiments, the other network 112 may be a WLAN.

A WLAN in Infrastructure Basic Service Set (BSS) mode may have an AccessPoint (AP) for the BSS and one or more stations (STAs) associated withthe AP. The AP may have an access or an interface to a DistributionSystem (DS) or another type of wired/wireless network that carriestraffic in to and/or out of the BSS. Traffic to STAs that originatesfrom outside the BSS may arrive through the AP and may be delivered tothe STAs. Traffic originating from STAs to destinations outside the BSSmay be sent to the AP to be delivered to respective destinations.Traffic between STAs within the BSS may be sent through the AP, forexample, where the source STA may send traffic to the AP and the AP maydeliver the traffic to the destination STA. The traffic between STAswithin a BSS may be considered and/or referred to as peer-to-peertraffic. The peer-to-peer traffic may be sent between (e.g., directlybetween) the source and destination STAs with a direct link setup (DLS).In certain representative embodiments, the DLS may use an 802.11e DLS oran 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS)mode may not have an AP, and the STAs (e.g., all of the STAs) within orusing the IBSS may communicate directly with each other. The IBSS modeof communication may sometimes be referred to herein as an “ad-hoc” modeof communication.

When using the 802.11ac infrastructure mode of operation or a similarmode of operations, the AP may transmit a beacon on a fixed channel,such as a primary channel. The primary channel may be a fixed width(e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling.The primary channel may be the operating channel of the BSS and may beused by the STAs to establish a connection with the AP. In certainrepresentative embodiments, Carrier Sense Multiple Access with CollisionAvoidance (CSMA/CA) may be implemented, for example in in 802.11systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, maysense the primary channel. If the primary channel is sensed/detectedand/or determined to be busy by a particular STA, the particular STA mayback off. One STA (e.g., only one station) may transmit at any giventime in a given BSS.

High Throughput (HT) STAs may use a 40 MHz wide channel forcommunication, for example, via a combination of the primary 20 MHzchannel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHzwide channel.

Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz,and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may beformed by combining contiguous 20 MHz channels. A 160 MHz channel may beformed by combining 8 contiguous 20 MHz channels, or by combining twonon-contiguous 80 MHz channels, which may be referred to as an 80+80configuration. For the 80+80 configuration, the data, after channelencoding, may be passed through a segment parser that may divide thedata into two streams. Inverse Fast Fourier Transform (IFFT) processing,and time domain processing, may be done on each stream separately. Thestreams may be mapped on to the two 80 MHz channels, and the data may betransmitted by a transmitting STA. At the receiver of the receiving STA,the above described operation for the 80+80 configuration may bereversed, and the combined data may be sent to the Medium Access Control(MAC).

Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. Thechannel operating bandwidths, and carriers, are reduced in 802.11af and802.11ah relative to those used in 802.11n, and 802.11ac. 802.11afsupports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space(TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and16 MHz bandwidths using non-TVWS spectrum. According to a representativeembodiment, 802.11ah may support Meter Type Control/Machine-TypeCommunications, such as MTC devices in a macro coverage area. MTCdevices may have certain capabilities, for example, limited capabilitiesincluding support for (e.g., only support for) certain and/or limitedbandwidths. The MTC devices may include a battery with a battery lifeabove a threshold (e.g., to maintain a very long battery life).

WLAN systems, which may support multiple channels, and channelbandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include achannel which may be designated as the primary channel. The primarychannel may have a bandwidth equal to the largest common operatingbandwidth supported by all STAs in the BSS. The bandwidth of the primarychannel may be set and/or limited by a STA, from among all STAs inoperating in a BSS, which supports the smallest bandwidth operatingmode. In the example of 802.11ah, the primary channel may be 1 MHz widefor STAs (e.g., MTC type devices) that support (e.g., only support) a 1MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes.Carrier sensing and/or Network Allocation Vector (NAV) settings maydepend on the status of the primary channel. If the primary channel isbusy, for example, due to a STA (which supports only a 1 MHz operatingmode), transmitting to the AP, the entire available frequency bands maybe considered busy even though a majority of the frequency bands remainsidle and may be available.

In the United States, the available frequency bands, which may be usedby 802.11ah, are from 902 MHz to 928 MHz. In Korea, the availablefrequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the availablefrequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidthavailable for 802.11ah is 6 MHz to 26 MHz depending on the country code.

FIG. 1D is a system diagram illustrating the RAN 113 and the CN 115according to an embodiment. As noted above, the RAN 113 may employ an NRradio technology to communicate with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The RAN 113 may also be in communication with theCN 115.

The RAN 113 may include gNBs 180 a, 180 b, 180 c, though it will beappreciated that the RAN 113 may include any number of gNBs whileremaining consistent with an embodiment. The gNBs 180 a, 180 b, 180 cmay each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the gNBs 180 a, 180 b, 180 c may implement MIMO technology. For example,gNBs 180 a, 108 b may utilize beamforming to transmit signals to and/orreceive signals from the gNBs 180 a, 180 b, 180 c. Thus, the gNB 180 a,for example, may use multiple antennas to transmit wireless signals to,and/or receive wireless signals from, the WTRU 102 a. In an embodiment,the gNBs 180 a, 180 b, 180 c may implement carrier aggregationtechnology. For example, the gNB 180 a may transmit multiple componentcarriers to the WTRU 102 a (not shown). A subset of these componentcarriers may be on unlicensed spectrum while the remaining componentcarriers may be on licensed spectrum. In an embodiment, the gNBs 180 a,180 b, 180 c may implement Coordinated Multi-Point (CoMP) technology.For example, WTRU 102 a may receive coordinated transmissions from gNB180 a and gNB 180 b (and/or gNB 180 c).

The WTRUs 102 a, 102 b, 102 c may communicate with gNBs 180 a, 180 b,180 c using transmissions associated with a scalable numerology. Forexample, the OFDM symbol spacing and/or OFDM subcarrier spacing may varyfor different transmissions, different cells, and/or different portionsof the wireless transmission spectrum. The WTRUs 102 a, 102 b, 102 c maycommunicate with gNBs 180 a, 180 b, 180 c using subframe or transmissiontime intervals (TTIs) of various or scalable lengths (e.g., containingvarying number of OFDM symbols and/or lasting varying lengths ofabsolute time).

The gNBs 180 a, 180 b, 180 c may be configured to communicate with theWTRUs 102 a, 102 b, 102 c in a standalone configuration and/or anon-standalone configuration. In the standalone configuration, WTRUs 102a, 102 b, 102 c may communicate with gNBs 180 a, 180 b, 180 c withoutalso accessing other RANs (e.g., such as eNode-Bs 160 a, 160 b, 160 c).In the standalone configuration, WTRUs 102 a, 102 b, 102 c may utilizeone or more of gNBs 180 a, 180 b, 180 c as a mobility anchor point. Inthe standalone configuration, WTRUs 102 a, 102 b, 102 c may communicatewith gNBs 180 a, 180 b, 180 c using signals in an unlicensed band. In anon-standalone configuration WTRUs 102 a, 102 b, 102 c may communicatewith/connect to gNBs 180 a, 180 b, 180 c while also communicatingwith/connecting to another RAN such as eNode-Bs 160 a, 160 b, 160 c. Forexample, WTRUs 102 a, 102 b, 102 c may implement DC principles tocommunicate with one or more gNBs 180 a, 180 b, 180 c and one or moreeNode-Bs 160 a, 160 b, 160 c substantially simultaneously. In thenon-standalone configuration, eNode-Bs 160 a, 160 b, 160 c may serve asa mobility anchor for WTRUs 102 a, 102 b, 102 c and gNBs 180 a, 180 b,180 c may provide additional coverage and/or throughput for servicingWTRUs 102 a, 102 b, 102 c.

Each of the gNBs 180 a, 180 b, 180 c may be associated with a particularcell (not shown) and may be configured to handle radio resourcemanagement decisions, handover decisions, scheduling of users in the ULand/or DL, support of network slicing, dual connectivity, interworkingbetween NR and E-UTRA, routing of user plane data towards User PlaneFunction (UPF) 184 a, 184 b, routing of control plane informationtowards Access and Mobility Management Function (AMF) 182 a, 182 b andthe like. As shown in FIG. 1D, the gNBs 180 a, 180 b, 180 c maycommunicate with one another over an Xn interface.

The CN 115 shown in FIG. 1D may include at least one AMF 182 a, 182 b,at least one UPF 184 a,184 b, at least one Session Management Function(SMF) 183 a, 183 b, and possibly a Data Network (DN) 185 a, 185 b. Whileeach of the foregoing elements are depicted as part of the CN 115, itwill be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The AMF 182 a, 182 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N2 interface and may serve as acontrol node. For example, the AMF 182 a, 182 b may be responsible forauthenticating users of the WTRUs 102 a, 102 b, 102 c, support fornetwork slicing (e.g., handling of different PDU sessions with differentrequirements), selecting a particular SMF 183 a, 183 b, management ofthe registration area, termination of NAS signaling, mobilitymanagement, and the like. Network slicing may be used by the AMF 182 a,182 b in order to customize CN support for WTRUs 102 a, 102 b, 102 cbased on the types of services being utilized WTRUs 102 a, 102 b, 102 c.For example, different network slices may be established for differentuse cases such as services relying on ultra-reliable low latency (URLLC)access, services relying on enhanced massive mobile broadband (eMBB)access, services for machine type communication (MTC) access, and/or thelike. The AMF 162 may provide a control plane function for switchingbetween the RAN 113 and other RANs (not shown) that employ other radiotechnologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP accesstechnologies such as WiFi.

The SMF 183 a, 183 b may be connected to an AMF 182 a, 182 b in the CN115 via an N11 interface. The SMF 183 a, 183 b may also be connected toa UPF 184 a, 184 b in the CN 115 via an N4 interface. The SMF 183 a, 183b may select and control the UPF 184 a, 184 b and configure the routingof traffic through the UPF 184 a, 184 b. The SMF 183 a, 183 b mayperform other functions, such as managing and allocating UE IP address,managing PDU sessions, controlling policy enforcement and QoS, providingdownlink data notifications, and the like. A PDU session type may beIP-based, non-IP based, Ethernet-based, and the like.

The UPF 184 a, 184 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N3 interface, which may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between the WTRUs 102a, 102 b, 102 c and IP-enabled devices. The UPF 184, 184 b may performother functions, such as routing and forwarding packets, enforcing userplane policies, supporting multi-homed PDU sessions, handling user planeQoS, buffering downlink packets, providing mobility anchoring, and thelike.

The CN 115 may facilitate communications with other networks. Forexample, the CN 115 may include, or may communicate with, an IP gateway(e.g., an IP multimedia subsystem (IMS) server) that serves as aninterface between the CN 115 and the PSTN 108. In addition, the CN 115may provide the WTRUs 102 a, 102 b, 102 c with access to the othernetworks 112, which may include other wired and/or wireless networksthat are owned and/or operated by other service providers. In oneembodiment, the WTRUs 102 a, 102 b, 102 c may be connected to a localData Network (DN) 185 a, 185 b through the UPF 184 a, 184 b via the N3interface to the UPF 184 a, 184 b and an N6 interface between the UPF184 a, 184 b and the DN 185 a, 185 b.

In view of FIGS. 1A-1D, and the corresponding description of FIGS.1A-1D, one or more, or all, of the functions described herein withregard to one or more of: WTRU 102 a-d, Base Station 114 a-b, eNode-B160 a-c, MME 162, SGW 164, PGW 166, gNB 180 a-c, AMF 182 a-b, UPF 184a-b, SMF 183 a-b, DN 185 a-b, and/or any other device(s) describedherein, may be performed by one or more emulation devices (not shown).The emulation devices may be one or more devices configured to emulateone or more, or all, of the functions described herein. For example, theemulation devices may be used to test other devices and/or to simulatenetwork and/or WTRU functions.

The emulation devices may be designed to implement one or more tests ofother devices in a lab environment and/or in an operator networkenvironment. For example, the one or more emulation devices may performthe one or more, or all, functions while being fully or partiallyimplemented and/or deployed as part of a wired and/or wirelesscommunication network in order to test other devices within thecommunication network. The one or more emulation devices may perform theone or more, or all, functions while being temporarilyimplemented/deployed as part of a wired and/or wireless communicationnetwork. The emulation device may be directly coupled to another devicefor purposes of testing and/or may performing testing using over-the-airwireless communications.

The one or more emulation devices may perform the one or more, includingall, functions while not being implemented/deployed as part of a wiredand/or wireless communication network. For example, the emulationdevices may be utilized in a testing scenario in a testing laboratoryand/or a non-deployed (e.g., testing) wired and/or wirelesscommunication network in order to implement testing of one or morecomponents. The one or more emulation devices may be test equipment.Direct RF coupling and/or wireless communications via RF circuitry(e.g., which may include one or more antennas) may be used by theemulation devices to transmit and/or receive data.

DETAILED DESCRIPTION

Medium Access and Transmission Procedures after Waking Up STAs Equippedwith WUR

STAs and APs equipped with WURs may be woken up for different reasons,such as network discovery, emergency alarms, buffered traffic for uplink(UL) and downlink (DL) transmissions, request for beacons, etc. Thedifferent wake up scenarios likely lead to different behaviors for STAsand APs.

Solutions for signaling the different reasons for waking up STAs and APand providing correct medium access and transmission procedures whenSTAs and APs are woken up and ready to conduct communications usingtheir primary connectivity radios (PCRs) are described herein.

In some embodiments a Wake Up Radio (WUR) may use one or more types ofWake Up Frames (WUFs). A WUR associated with a STA may use a Wake UpRequest Frame (WUReqF) to request that one or more STAs to wake up byturning on their primary connectivity radios (PCRs). FIG. 2 illustratesan example design of a wake up request frame (WUReqF) 200, in accordancewith some embodiments.

The WUReqF may contain one or more of the following parts: a preamble202 which may include a regular WLAN preamble and/or a WUR preamble, aMAC header 204, a frame body 206 and/or a FCS field 208. In someembodiments, the WUReqF may include other parts such as a packetextension, a control trailer, etc.

As shown in FIG. 2 the WUReqF 200 may include one or more of thefollowing fields: a UL/DL indicator 210, a Request/Response Indication212, a WUF Purpose field 214, a WU Scheduling field 216, a TX/RXCapabilities field 218, a Traffic Priority Indication field 220, aTraffic Indication field 222, a BSS/ESS Identification field 224, and aSecurity ID field 226.

In some embodiments, the uplink/downlink (UL/DL) Indicator 210 indicatesif the Wake Up frame is sent (i) in the Uplink direction (from STA toAP), (ii) in the Downlink direction (from AP to STA), (iii) in a peer topeer fashion (from a non-AP STA to another non-AP STA), or (iv) in a APto AP fashion (from an AP to another AP). In some embodiments, the UL/DLIndicator uses one bit with one value indicating the WUF is sent in theUplink direction and the other value indicating that the WUF is sent inthe Downlink direction. In an alternative embodiment, two bits are used,using for example the value “00” to indicate peer to peer WUFtransmissions, “01” to indicate Downlink transmission of WUF, “10” toindicate Uplink WUF transmissions, and using “11” to indicate AP to APWUF transmissions. In some embodiments, the UL/DL Indicator is includedin the preamble or MAC header, or any other part of the WUF, such asPacket Extension and Control Trailers. Alternatively, the UL/DL Indictormay be implemented using scrambler seeds, phase rotations betweensymbols, etc.

In some embodiments, Request/Response field 212 identifies whether theWake Up Frame is a Wake up request frame or response frame. Inalternative embodiments, the Request/Response frame is identified usingone or more bits in the Preamble or MAC header or any other part of theframe, for example, in the Type/Subtype field in the MAC header.

In some embodiments, one or more STA identifiers may be included, suchas MAC addresses, Association Identification (AIDs), or any other typesof identifiers for one or more STAs that are requested to be woken up.

In some embodiments, the Wake Up Frame (WUF) Purpose field 214 mayinclude information identifying one or more purposes as to why the WUFis sent to wake up the primary connectivity radio associated with theSTA that is targeted. In some embodiments, this field indicates one ormore of the following: (Re)Association, Authentication, Disassociation,(DL/UL/Peer to Peer) data transmission, Status Inquiry, EmergencyReporting, General, Max Idle Period Reached, Request for Beacon, TDLSEstablishment, TDLS De-establishment, Route Discovery, Request to Listento Beacon, Request to Listen to TIM, Timing Synchronization Function(TSF) Timer Update, Max Idle Period Expiring, etc.

In some embodiments, the Wake Up Scheduling field 216 may includescheduling and configuration for the primary connectivity radio of thetargeted STAs after they are awake. In some embodiments, this fieldindicates whether the primary connectivity radio of the targeted STAwill transmit or receive. For example, the WU Scheduling field mayinclude a duration after which the targeted STA is requested to wake uptheir primary connectivity radio and to start transmitting or receiving.The duration may be referenced to a TSF Timer value (which in someembodiments may be included in the WUF or remembered from a previoustransmission), or to the end of the current WUF. In some embodiments,the WU Scheduling field may also include the specific channel,bandwidth, and allocation to be used by the primary connectivityradio(s) for transmission or subsequent receptions. The WU Schedulingfield may include channel quality information as well, e.g. interferencemeasured at the WUR transmitter and/or its transmitted power level, toaccelerate and improve chances of successful reception of any PCR(s)transmissions back to the WUR transmitter.

In some embodiments, in the TX/RX Capability field 218, one or moreTX/RX capabilities and TX/RX modes that the transmitting STA currentlysupports may be included. Such modes may include the following:

-   -   TX/RX Mode: which may include single user (SU), multi user (MU),        MU OFDMA, MU MIMO, the number of Spatial Streams, the number of        spatial time streams, and the TX/RX bandwidth/resource units        (RUs) that the transmitting STA currently supports.    -   TX/RX Band: the operating band(s) of the STA's PCR, including        Sub 1 GHz, 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and/or 60 GHz, or        other bands. The band(s) may be indicated by a value or one or        more bits in a bit map.    -   TX/RX Bandwidth: which may indicate the capabilities of the        transmitting STAs that are capable of transmit and/or receive.        Values for this field may include one or more 5 MHz, 10 MHz, 20        MHz, 40 MHz, 80 MHz, 160 MHz, 80+80, or any large or smaller        bandwidth such as RUs, and/or down-/up-clocked bandwidths.    -   WUR RX: which may indicate whether the WUF transmitter has a WUR        receiver. In some embodiments, WUR transmitters only expect to        receive from WLAN PCRs.

In some embodiments, the Traffic Priority Indication field 220 is usedto indicate the traffic that is buffered for the targeted STAs. In onesuch embodiment, the priorities and/or access categories for any or thehighest priority buffered traffic are included. Some values for thisfield may include Status Polling, Emergency Reporting, UL/DL DataRequested, UL/DL Data Reported, and Max Idle Period Exceeded.Additionally or alternatively, traffic priority for buffered trafficintended for the targeted STA may be included such as VI, VO, BK, BE. Inan alternative embodiment, a hash of a selection of traffic priority isincluded.

In some embodiments, the Traffic Indication field 222 is used toindicate the size or the amount of buffered traffic, which may beintended for the targeted STA. In some embodiments, Traffic Indicationfield indicates whether there is traffic buffered for the targeted STA.Additionally or alternatively, the size of buffered traffic may beincluded, for example, the number of packets, the size of each or allpackets, the estimated time needed to transmit one or more or allbuffered traffic.

In some embodiments, the BSS/SS/ESS Identification field 224 is used toidentify one or more BSS or ESS for which the WUF is intended. In onesuch embodiment, one or more IDs of BSS or SS, or ESS are included inthis field, such as BSSID, ESSID, SSID, BSS Color. In alternativeembodiments, a hash of one or more IDs of BSS, SS or ESS or otheridentifiers may be included.

In some embodiments, the Security ID field 226 is used to indicatesecurity related information. In at least one such embodiment, thisfield includes one or more secure password or phrases that both thetransmitting and targeted STAs agreed upon before one or both them wentinto the sleep state. In alternative embodiments, this field includesthe answer to a challenge phrase that was sent by the targeted STA. Thechallenge phrase may be contained in an earlier WUF or in a frame thatwas sent by the primary connectivity radio (PCR) of the targeted STAbefore one or both of them went into the sleep state. In one example,the challenge phrase may be sent in a response frame to a STA if a SleepNotification frame has been received from that STA. In another example,a secure password or phrase will be sent in response to a STA if a SleepNotification frame has been received from that STA. In yet anotherexample, a secure password or phrase is sent by a STA in a frame thatnotifies another STA that it is going into the sleep state and will turnoff its PCR.

In some embodiments, a WUR associated with a STA uses a Wake Up ResponseFrame (WURespF) to respond to one or more received WUReqFs.Additionally, a WUR associated with a STA, for example, an AP, may use aWURespF to wake up one or more STAs, which in some scenarios may takeplace before the STA receives any WUReqF. FIG. 3 illustrates a design ofa wake up response frame (WURespF) 300, in accordance with someembodiments. It should be noted that any frame received from theintended recipient's WUR or PCR within a wide interframe space (WIFS)(IFS period short IFS (SIFS) and <DCF IFS (DIFS)), may be used forindicating successful reception of the WUReqF.

As shown, the WURespF 300 may include many of the same fields as theWUReqF, however it additionally includes a Result Code field 302. Insome embodiments, the Result Code field includes the response to theWUReqF. In at least one such embodiment, the Result Code field includesone or more of an ACK, deferred access, rejection, and success. Thisinformation may be indicated in any part of the WUF, such as in thepreamble 305 or MAC header 310. For example, a WUR ACK frame may beindicated by the Type and Subtype field in the preamble and/or MACheaders.

Further, the WURespF includes information 312 indicating one or moresets of TX/RX modes and configurations to be used by the WUR and/or PCRof one or more targeted STA(s), possibly at the time as indicated in theWU Scheduling field 314. The configuration information may include thefollowing:

-   -   TX/RX Mode: which may include SU, MU, MU OFDMA, MU MIMO, the        number of Spatial Streams, the number of spatial time streams,        and the TX/RX bandwidth/RUs that the targeted STA(s) should use.    -   TX/RX Band: the operating band(s) that the targeted STAs should        use, with values and/or bits indicating values including Sub 1        GHz, 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and/or 60 GHz, or other        bands. The band(s) may be indicated by a value or one or more        bits in a bit map.    -   TX/RX Bandwidth and resource allocation for the targeted STAs        for TX and/or RX. Values for this field may include one or more        5 MHz, 10 MHz, 20 MHz, 40 MHz, 80 MHz, 160 MHz, 80+80, or any        large or smaller bandwidth such as RUs, and/or down-/up-clocked        bandwidths, as well as the RUs and/or (sub)channels assigned to        the targeted STAs.

It is worth noting that any part(s) of the WUReqF and/or WURespF, or anycombination thereof, may be implemented in any form, including anypart(s) of any WUF format, regular 802.11 formats, information elements,control frame, management frames, extension frames, NDP frames, PHY-onlyframe, scramblers seeds, phrase rotations, MAC and PHY headers,including WUR preambles and regular preambles, or PHY-Only Frame.

Medium Access Procedures when AP is Woken Up for Association

In some embodiments, a method for waking up an AP for association andthe medium access procedure for an STA and AP using their primaryconnectivity radio (PCRs) after the AP is woken up includes an STA,(e.g., STA1), equipped with a WUR sending a WUF such as a WUReqF todiscover a suitable AP. In some embodiments, STA1 may include abroadcast or multicast WUReqF, a list or a hash of identifiers for oneor more of BSS's, SS's, ESS's, such as BSSIDs, SSIDs, ESSIDs, HESSIDs,BSS Color, etc. that are of interest in the WUReqF. Additionally, STA1may also include one or more the following information in the WUReqF:

-   -   Uplink direction transmission.    -   TX/RX capabilities: TX/RX capabilities including the generation        of STA1, the bandwidth and operating class supported by STA1,        the SU, MU, OFDMA, MU-MIMO mode supported by STA1, the operating        band supported by STA1, the RU granularity supported by STA1,        etc. STA1 may also indicate a preferred operating band,        bandwidth or mode.    -   STA Type: such as mobile phone, sensors, meters, laptops, sensor        backhauls, front hauls.    -   Buffered traffic priority and indication: the priority and        indication of any buffered traffic for UL transmission.    -   Security Credentials: security credentials that may be        previously established, for example, in the Security ID field.    -   WUR RX: may indicate whether the WUF transmitter has a WUR        receiver. In some embodiments, WUR transmitters only expect to        receive from WLAN PCRs.

STA1 may send a unicast WUReqF to a particular AP, (e.g., AP1), if ithas pre-acquired information indicating APIs presence. In someembodiments, STA1 may have pre-acquired information through a differentnetwork connection such as cellular or License Assisted Access (LAA),through previous visit and association, or through directions from otherAPs. In some embodiments, STA1 may have received a WUR reference signalor (short) beacon from AP1. In some embodiments, STA1 may includeindication in the unicast WUReqF that it has pre-acquired information,such as through a previous connection, and may also include in theWUReqF information indicating one or more of the following:

-   -   AP-CSN (AP Configuration Sequence Number): the AP-CSN or        compressed AP-CSN that STA1 has acquired from a previous        association or in any other manner.    -   A Common Advertisement Group (CAG) Number or a compressed CAG        that STA1 has acquired from a previous association or in any        other manner on, e.g., network services provided.    -   Security Credentials: security credentials that were previously        established, for example, in the Security ID field.

If STA1 has not received a response to its WUReqF on a channel for acertain duration, and/or it has not received any (short) beacon,measurement pilots, probe response, or FILS Discovery frame, STA1 mayswitch to another channel and restart the WUR AP discovery process.

In some embodiments, if AP1 receives a WUReqF from STA1, AP1 mayrecognize that STA1's purpose is (re)association because it is eitherindicated by the purpose of WUReqF, AP1 has recognized that STA1 is notcurrently associated with itself, or AP1 has detected that one or moreidentifiers of BSSs, SSs, ESSs, are included in the WUReqF. In someembodiments, AP1 may ignore the WUReqF if its own BSSID, SSID and/orESSID, BSS Color, are not included in the WUReqF. AP1 may ignore theWUReqF if the security credentials included do not match its record orare not correct. In some embodiments, AP1 may ignore the WUReqF if itdoes not support and/or prefers not to support any of the TX/RXconfigurations or the STA's preferred TX/RX configurations. In someembodiments, AP1 may ignore the WUReqF if it is targeted to its SS orESS, and AP1 is not scheduled to respond. In some embodiments, AP1 mayignore the WUReqF if STA1 is not a type of STA that the AP1 supportsand/or prefers.

In some embodiments, the AP1 may respond to the WUReqF with a WURespF ora PCR response if one or more the following conditions are met:

-   -   The WUReqF is for (re)association purposes.    -   The STA is a type of STA that AP1 supports and/or prefers.    -   The WUReqF includes a list or hash or identifiers for BSSs, SSs,        ESSs, or BSS Color, to which AP1 belongs.    -   The WUReqF is a unicast frame targeted at the AP1.    -   The security information included are verified if such security        information is included in the WUReqF.    -   AP1 is the responding AP for its SS and/or ESS.    -   AP1 supports and/or prefers to support one or more STA1's        generation, (preferred) operating band, bandwidth, TX/RX mode.    -   The priority/type of traffic buffered at the STA1 met the        requirements of AP1.

In some embodiments, the AP1 may respond to a single WUReqF with aWURespF or a PCR response, which may be a unicast and/orbroadcast/multicast frame. If AP1 receives multiple WUReqFs from morethan one STA, it may respond with a broadcast or multicast WURespF orPCR response, which may include the identifiers of one or more STAs fromwhich it received the WUReqF. If AP1 has identified that one or more STAhas sent WUReqFs for the purpose of (re)association, AP1 may include inthe WURespF or in the PCR response a scheduling including a time atwhich a broadcast probe response or (short) beacon will be transmitted,using the AP's PCR in some embodiments.

In some embodiments, AP1 may include a version of the TSF timer, such asthe 4, 2 or 1 least significant bytes of the TSF timer, full TSF Timer,or a compressed TSF timer. In some embodiments, the schedulinginformation included in the WURespF or in the PCR response may referencethe TSF timer value.

In some embodiments, if the WUReqF includes a (compressed) AP-CSN and/orCAG Number that is associated with AP1, AP1 may provide in the WURespFor in the PCR response whether the AP-CSN and/or CAG Number is current.If the AP-CSN is no longer current, AP1 may indicate a time in theWUReqF, at which time the PCR of the AP may wake up and send adifferential probe response frame including the changed informationcompared to the previous AP-CSN. In some embodiments, if the CAG Numberis no longer current, AP1 indicates the CAG is no longer current it inthe WURespF or in the PCR response, so that the STA and AP may startANQP procedures after association.

In some embodiments, AP1 indicates to one or more STAs whether STA1should transmit or receive at an indicated time interval, in the WURespFor in the PCR response. In some embodiments, AP1 indicates which band,bandwidth, RU, and/or spatial stream STA1 or each of the STAs should beusing for their PCR. In some embodiments AP1 indicates which TX/RX mode,(e.g., SU, MU, OFDMA, MU-MIMO) STA1 should use. In another example, suchspecifications may be sent in another WUF, such as a WU Trigger frame,which may be transmitted at a time indicated in the WURespF. In somealternative embodiments, a PCR Trigger frame is transmitted to triggeruplink transmissions by the one or more STAs after a wake up time ofAPIs PCR, which may be indicated in the WURespF or in the PCR response.In yet another embodiment, AP1 transmits a WURespF or a PCR responsesimply to acknowledge the reception of the WUReqF. Another WUF, such asWU Trigger frame or Wake-up notification frame, may be transmitted laterto provide additional information, such as TX/RX mode, TX/RX band,bandwidth, RU, spatial streams. In some embodiments, such a frame istransmitted by the WUR or PCR.

In some embodiments, in response to receiving a WURespF or WU Triggerframe, STA1 switches its PCR to the correct operating bandwidth, band,and TX/RX mode and follows the instruction to be in TX or RX mode usingits PCR, possibly at or before the time indicated by the WURespF and/orWU Trigger frame, using SU or MU mode as indicated to continue probing,authentication, and (re)association process following the instruction ofthe WURespF and/or WU Trigger frame. If a PCR Trigger frame istransmitted by AP1, then STA1 follows the instructions to conductprobing, authentication, and (re)association process following theinstruction of the PCR Trigger frame.

In some embodiments, scheduling of medium access for STA1 is determinedby the AP based on the buffered traffic priority, size of the bufferedtraffic, and/or type of the STAs.

Medium Access Procedures when AP is Woken Up for UL Transmission

In some embodiments, a procedure for a STA to wake up an AP for ULTransmissions and the procedure for medium access for the STA and AP toconduct such UL transmissions includes sending, using STA1 equipped witha WUR, a WUReqF to wake up an associated AP1 when it has informationindicating that AP1 is currently in a sleep state. In some embodiments,STA1 includes in the WUReqF information indicating one or more thefollowing:

-   -   Purpose of the WUReqF is uplink (UL) data transmission, or        emergency reporting, status report.    -   Uplink direction transmission.    -   TX/RX mode: TX/RX mode changes as compared to the last        communications between STA1 and AP1 or the current TX/RX        mode/configurations used by STA1's PCR. Example configurations        include the SU, MU, OFDMA, MU-MIMO modes, the RU granularity        supported by STA1, and a number of spatial streams, etc. In some        embodiments, STA1 also indicates a preferred bandwidth, RU or        mode.    -   Buffered traffic priority and indication: the priority and        indication of any buffered traffic for UL transmission.    -   Security Credentials: security credentials that may be        previously established, for example, in the Security ID field.    -   Specific channel, bandwidth, and allocation to be used by the        primary radio(s) for transmission or subsequent receptions.        Channel quality information may be included as well, e.g.        interference measured at WUR transmitter and/or transmitted        power level, to accelerate and improve chances of successful        reception of any PCR(s) transmissions back to WUR transmitter.    -   WUR RX: may indicate whether the WUF transmitter has a WUR        receiver. In some embodiments, WUR transmitters only expect to        receive from WLAN PCRs.

In some embodiments, STA1 sends a unicast WUReqF to AP1 includinginformation indicating one or more of the following:

-   -   AP-CSN (AP Configuration Sequence Number): the AP-CSN that STA1        acquired prior to the STA1 went to sleep. The AP-CSN may be of a        compressed form.    -   CAG Number: the Common Advertisement Group Number that STA1        acquired prior to the STA1 going to sleep. The CAG Number may be        of a compressed form.    -   Security Credentials: security credentials that were previously        established, for example, in the Security ID field.

In some embodiments, AP1 receives a WUReqF from STA1. In suchembodiments, AP1 recognizes that STA1's purpose is (UL) datatransmission based on an indication of the purpose of WUReqF, or AP1detects that STA1 is associated with itself and the WUReqF includestraffic indications. In some embodiments, AP1 may ignore the WUReqF ifthe security credentials included do not match its record or are notcorrect.

In some embodiments, AP1 responds to the WUReqF with a WURespF or with aPCR response. In some embodiments, AP1 may respond to one or more WUReqFwith a broadcast/multicast WUR frame or a broadcast/multicast PCR frameto announce that it is awake and may be ready to receive. In someembodiments, AP1 responds to a single WUReqF with a WURespF or with aPCR response, which may be a unicast and/or broadcast/multicast frame.In some embodiments, if AP1 has received multiple WUReqFs from more thanone STA, AP1 responds with a broadcast or multicast WURespF or PCRresponse, which may contain the identifiers of one or more STAs fromwhich it has received WUReqF. In some embodiments, AP1 identifies thatone or more STA has sent WUReqFs for the purpose of (UL) datatransmission and includes a scheduling in the WURespF or in the PCRresponse, such as a time at which a trigger frame may be transmitted byAPIs WUR and/or PCR. Alternatively, AP1 may include a scheduling in theWURespF or in the PCR response that is a time at which STA1 may starttransmitting. In some embodiments, the scheduled time corresponds to atime after a frame sent by APIs PCR.

In some embodiments, AP1 includes a version of the TSF timer, such as 4,2 or 1 least significant bytes of the TSF timer, full TSF Timer, orcompressed TSF timer, e.g., to provide synchronization for one or moreSTAs. The scheduling information that may be included in the WURespF orin the PCR response may reference to this TSF timer value.

If the WUReqF includes (compressed) AP-CSN and/or CAG Number that areassociated with AP1, AP1 may indicate whether the AP-CSN and/or CAGNumber is current in the WURespF, or in the PCR response. If the AP-CSNis no longer current, the AP may indicate a time in the WUReqF at whichthe PCR of the AP may wake up and send a differential probe responseframe including the changed information compared to the previous AP-CSN.If the CAG Number is no longer current, AP1 may provide an indication inthe WURespF or in the PCR response so that the STA and AP may start ANQPprocedures using their PCRs.

In some embodiments, AP1 indicates any (DL) buffered traffic, such astraffic priority and/or size, for one or more STAs in the WURespF or inthe PCR response.

In some embodiments, AP1 provides an indication to one or more STAs,e.g., STA1 via the WURespF or the PCR response whether STA1 should (i)transmit or receive at an indicated time interval; (ii) and/or whichband, bandwidth, RU, and/or (iii) spatial stream STA1 or each of theSTAs should be using for their PCR; (iv) and/or which TX/RX mode, suchas SU, MU, OFDMA, MU-MIMO, STA1 should use. In another embodiment, suchspecifications are sent in another WUF, such as a WU Trigger frame,which may be transmitted at the time indicated in the WURespF or PCRresponse. In another embodiment, a PCR Trigger frame is transmitted totrigger uplink transmissions by the one or more STAs after a wake uptime of APIs PCR, which is indicated in the WURespF or the PCR response.In yet another alternative embodiment, AP1 transmits a WURespF or PCRresponse simply to acknowledge the reception of the WUReqF; another WUF,such as WU Trigger frame, or Wake-up notification frame may betransmitted later to provide additional information, such as TX/RX mode,TX/RX band, bandwidth, RU, spatial streams; such a frame may betransmitted by the WUR or PCR.

Subsequent to receiving a WURespF or a PCR response, or WU Triggerframe, STA1 may switch its PCR to the correct operating bandwidth, band,TX/RX mode and may follow the instruction to be in TX or RX mode usingits PCR, possibly at or before the time indicated in the WURespF, thePCR response, and/or WU Trigger frame, using SU or MU mode as indicated,to continue the UL/DL data transmissions following the instruction ofthe WURespF, the PCR response, and/or WU Trigger frame. If a PCR Triggerframe is transmitted by AP1, then STA1 should follow the instructions toconduct UL/DL data transmissions process following the instruction ofthe PCR Trigger frame.

Medium Access Procedures when a STA is Woken Up for UL/DL Transmission

In some embodiments, it may be desirable for an STA to wake up anotherSTA to transmit to and/or to receive from that STA. For example, it maybe desirable for an STA to wake up its AP to transmit its UL data and/orto receive any buffered data from the AP. Further, it may be desirablefor an STA to wake up a peer to peer STA with which it has established apeer to peer connection to transmit to and/or to receive from that STA.

In some embodiments, a procedure for an STA to wake up another STA forUL/DL/Peer2Peer transmissions and the procedure for medium access forthe STAs to conduct such UL/DL/Peer2Peer transmissions includes an STA,e.g., STA1 (which may be a non-AP STA or AP), equipped with a WURsending a WUF such as a WUReqF to wake up one or more other STAs, e.g.,STA2, e.g., when it has information indicating that STA2 is currently ina sleep state. STA1 may include information indicating one or more thefollowing in the WUReqF:

-   -   Purpose of the WUReqF is (UL/DL/Peer2Peer) data transmission, or        emergency reporting, status report, etc.    -   Downlink/Peer2Peer direction transmission.    -   TX/RX mode: TX/RX mode changes as compared to the last        communications between STA1 and STA2 or the current TX/RX        mode/configurations used by STA1's PCR, for example, the SU, MU,        OFDMA, MU-MIMO mode, the RU granularity supported by STA1,        number of spatial streams, etc. STA1 may also indicate a        preferred bandwidth, RU or mode. Additionally or alternatively,        STA1 may indicate the TX/RX mode/configuration that STA2's WUR        or PCR may adopt for responding to the WUReqF, such as SU, MU,        OFDMA, MU-MIMO mode, the RU granularity, number of spatial        streams, band, allocated bandwidth/channels/RUs, etc. In        addition, it may be specified whether the PCR/WUR of STA2 may be        in TX or RX mode at a scheduled time or when the PCR is turned        on. In at least one embodiment, the WUReqF includes a flag or        signal that optionally requests an acknowledgement. In some        embodiments, the WUReqF also includes a flag that indicates the        allowable delay before an acknowledgement/WURespF is returned.        If the transmitter is not receiving an ACK within the desired        delay, it may trigger a retransmission of the WUF. The WURespF        may be sent using code division, sub-channel or random access        based methods detailed below.    -   In some embodiments, STA1 indicates the TX/RX mode/configuration        that STA2's PCR may adopt for UL/DL/Peer2Peer transmissions,        such as SU, MU, OFDMA, MU-MIMO mode, the RU granularity, number        of spatial streams, band, allocated bandwidth/channels/RUs, etc.    -   Buffered traffic priority and indication: the priority and        indication of any buffered traffic for UL transmission.    -   Security Credentials: security credentials that may be        previously established, for example, in the Security ID field.    -   Channel quality information: e.g. interference measured at the        WUR transmitter and/or transmitted power level, to accelerate        and improve chances of successful reception of any PCR(s)        transmissions back to the WUR transmitter.    -   WUR RX: may indicate whether the WUF transmitter has a WUR        receiver. In some embodiments, WUR transmitters only expect to        receive from WLAN primary radios.

In some embodiments, STA1 sends a unicast WUReqF to STA2 or abroadcast/multicast WUF to one or more STAs including informationindicating one or more of the following:

-   -   Request to listen to beacon indication indicating that STA2        needs to turn on its PCR to listen to the beacon for updated        information of the BSS. In some embodiments, an AP may transmit        a WU (short) beacon which may include an AP-CSN number. If an        STA detects that its associated AP has updated the AP-CSN count,        it may turn on its PCR and listen to the next (short) beacon at        the next TBTT or TSBTT.    -   CAG Number: the Common Advertisement Group Number that STA1        currently has.    -   Security Credentials: security credentials that were previously        established, for example, in the Security ID field.

If STA2 receives a WUReqF from STA1, STA2 may recognize that STA1'spurpose is (UL/DL/Peer2Peer) data transmission because it is eitherindicated by the purpose of WUReqF, or STA2 has detected that STA1 isits AP or has an established Peer2Peer connection and there are trafficindications included in the WUReqF. In some embodiments, STA2 ignoresthe WUReqF if the security credentials included do not match its recordor are not correct.

In some embodiments, STA2 responds to the WUReqF with a WURespF or a PCRresponse. Such a response may be sent in SU or MU mode, as indicated bythe TX/RX mode/configuration contained in the WUReqF. In someembodiments, the WURespF/PCR response includes scheduling informationwhen the PCR of STA2 will be turned on. The WURespF may also include:

-   -   TX/RX mode: TX/RX mode changes as compared to the last        communications between STA1 and AP1 or the current TX/RX        mode/configurations used by STA1's PCR, for example, the SU, MU,        OFDMA, MU-MIMO mode, the RU granularity supported by STA2,        number of spatial streams, etc. STA1 may also indicate a        preferred bandwidth, RU or mode.    -   Buffered traffic priority and indication: the priority and        indication of any buffered traffic for UL/Peer2Peer        transmission.

In some embodiments, STA1 includes a scheduling time at which a triggerframe may be transmitted by STA1's WUR and/or PCR. In such embodiments,the scheduling time is included in a WUReqF, an additional WUF, or a PCRframe. In alternative embodiments, STA1 may include a scheduling time atwhich STA2's PCR may start transmitting/receiving, possibly after aframe sent by STA1's PCR. In such embodiments, the scheduling time isincluded in the WURespF or another WUF, such as a WU Trigger frame.

In some embodiments, STA1 indicates to one or more STAs, e.g., STA2, inthe WUReqF, whether STA2 should (i) transmit or receive at an indicatedtime; and/or (ii) which band, bandwidth, RU, and/or (iii) spatial streamSTA1 or each of the STAs should be using for their PCR; and/or (iv)which TX/RX mode, such as SU, MU, OFDMA, MU-MIMO, STA1 should use. Insome embodiments, such specifications are sent in another WUF, such asWU Trigger frame, which may be transmitted at a time indicated in theWUReqF or following the WURespFs or PCR responses received. Inalternative embodiments, a PCR SU/MU transmission is sent by STA1 to oneor more STAs including STAs that are indicated by any of the sent WUFs.In some embodiments, a PCR Trigger frame is transmitted to triggeruplink transmissions by the one or more STAs after a wake up time ofSTA1's PCR, which may be indicated in the WUReqF or any other WUFs. Insome embodiments, STA2 transmits a WURespF or PCR response simply toacknowledge the reception of the WUReqF; another WUF, such as WU Triggerframe, or PCR Wake-up notification frame may be transmitted later toprovide additional information, such as TX/RX mode, TX/RX band,bandwidth, RU, spatial streams for one or more STAs including STA2. Sucha frame may be transmitted by the WUR or PCR of STA1.

In response to receiving a WUReqF, WUF, or WU Trigger frame, STA2 mayswitch its PCR to the correct operating bandwidth, band, TX/RX mode andmay follow the instruction to be in TX or RX mode using its PCR. STA2may switch possibly at or before the time indicated in the WUReqF, WUTrigger, or WUF, using SU or MU mode as indicated to continue theUL/DL/Peer2Peer data transmissions following the instruction of theWUReqF, WU Trigger frame, WUF, or PCR's SU/MU transmissions. If a PCRTrigger frame is transmitted by STA1, then STA2 should follow theinstructions to conduct UL/DL data transmissions process following theinstruction of the PCR Trigger frame.

To achieve higher MAC efficiency, STA2 may switch on its PCR andtransmit buffered status or management, data, control or extensionframes via the UL in response to receiving a WUReqF, or WUF, for wakingup STAs for UL transmission, status report, etc., In such embodiments,STA2 may avoid transmitting a frame, such as a WUR frame, PCR frame or aPS-Poll frame, to alert STA1 that STA2 is awake. If STA1 has transmittedone or more WUFs to STA2, then any valid packets transmitted by the PCRof STA2 correctly received by STA1 is an indication that STA2 issuccessfully woken up. In some embodiments, the valid packets mayinclude e.g., any management, control, data, extension frames, ACK andACK no ACK frames. If a PCR Trigger frame is transmitted by STA1, thenSTA2 may follow the instructions to conduct UL/DL data transmissionsprocess following the instruction of the PCR Trigger frame.

In some embodiments, after receiving a WUReqF, WUF, or WU Trigger Framefor waking up STAs for DL transmission, or emergency report, STA2 mayresponsively turn on its PCR and initiate reception. In someembodiments, the PCR is configured by the configurations indicated byany of the received WUF and/or PCR frames. If STA2 has not received avalid frame from STA1, after some period of time such as someDelay_Threshold (either uni-cast or as part of a MU PPDU), STA2 may sendSTA1 a frame to alert STA1 that STA2 is awake and ready to receive anyDL packets. In some embodiments, the frame sent by STA2 may be a PS-Pollframe or any other management, control, data or extension frame, a NDPframe, NDP MAC frame. In some embodiments, the frame sent by STA2 mayalso be a data frame if STA2 includes any data frames to transmit toSTA1. In response to receiving a valid frame from STA2, STA1 determinesthat STA2 is awake and that STA1 may transmit any packets to STA2. IfSTA1 does not have any packets for transmission to STA2, it may indicatesuch information in a frame transmitted to STA2 and may indicate to STA2that STA2 may go to sleep and turn on WUR when ready.

In some embodiments, a STA completes a UL data transmission when wokenup using a wake up packet that does not contain a purpose indication.

FIG. 7 illustrates a procedure for UL data transmission when a Wake UpPacket (WUP) does not include a purpose indication. As shown, when aSTA's PCR is off, the AP transmits a WUR packet 702 with no purposeindication in the WUP, causing additional overhead (packet exchanges).When the AP's PCR is on, and the STA PCR is off, STA transmits a PS-Poll704 and AP responds with a UL Data Poll 706 or DL packet which containsrequest for UL data transmission. After the polling, the STA transmitsUL data 708 and the AP transmits an ACK 710.

In some embodiments, if the WUP has no purpose indication, it can signalthat a STA2 can go to sleep and turn on its WUR when ready.

In some embodiments, a STA completes a UL data transmission when wokenup when a WUP includes a purpose indication.

In the example of FIG. 8, a STA's PCR is off and an AP has PCR on. TheAP transmits a WUP 802 with a purpose indication, e.g., such a purposeindication may be Request UL data transmission, and the STA respondswith UL data 804. The AP then transmits an ACK 806. As shown, thepresence of a purpose indication decreases the number of packetexchanges.

In some embodiments, a WUR (Re)configuration procedure takes place inwhich a Wake Up packet does not contain the purpose indication, as shownin FIG. 9. FIG. 9 illustrates a medium access procedure in which a STAis woken up for configuration/reconfiguration, such as reconfigurationof sleeping/wake-up/monitoring schedules, and/or wake up channels, etc.Such a process may be a part of association/reassociation procedure, orafter an AP makes a determination to change its configurations for a STAor for its BSS. More specifically, as shown in FIG. 9, packet exchangesoccur when an AP transmits a WUP 902 without a purpose indicationrelating to a configuration or reconfiguration. When the STA's PCR isoff and the STA receives the WUP without a purpose indication of a(re)configuration, the STA transmits a power save polling (PS-Poll) 904to the AP. The AP responds with a configuration request 906, and the STAresponds with configuration preferences 908. The AP responds withconfiguration Confirm packet 910 to confirm a configuration, which theSTA acknowledges by sending a ACK or BA 912.

In some embodiments, an AP WUR (re)configuration procedure saves packetexchanges and reduces overhead and hence provides additional powersaving by including a purpose indication in the WUP. In the example ofFIG. 10, a WUP 1002 is sent from the AP to the STA that includes apurpose indication, e.g., the purpose indication may be Configuration,Reconfiguration, (re)configuration of sleep/wake up/monitoringschedules, and/or (re)configuration of wake up channels, therebyallowing the STA to respond with configuration preferences 1004 insteadof a power saving polling. For example, when the STA receives the WUPwith a purpose indication of (re)configuration, the STA may directlyrespond with a configuration preference packet 1004 to indicate itspreference for the configurations that the AP/STA will negotiate. The APcan then respond with configuration requests 1006. The STA transmits aconfirmation 1008 of the configuration and the AP responds with an ACK1010. After the STA receives the ACK, it may go into sleep by turningoff its PCR.

Combined WUR and Primary Connectivity Radio Packets for STA when WokenUp for UUDL Transmission

An STA (which may be a non-AP STA or an AP) may wake another STA(s) totransmit to and/or to receive from the woken-up STA(s). For example, itmay be desirable for an AP to wake up the STA to transmit DL data and/orto receive any buffered data from the STA. The STA or AP may makeefficient use of the medium by transmitting the WUR and primaryconnectivity radio (PCR) packets consecutively within the same initialtransmission, thus saving the time that would have been used to accessthe medium a second time for the transmission of the PCR packet, asshown in FIG. 11. FIG. 11 illustrates a WUR packet 1102 and a PCR packet1104 in a single transmission. Alternatively, the WUR packet and the PCRpacket may be separated by a time period such as a SIFS time, which maypreserve the medium access. FIG. 12 illustrates an example ofconsecutive transmission of a WUR packet 1202 and a PCR packet separatedby an IFS, which may be an SIFS time.

In some embodiments, a STA may first transmit several WUR packets towake up one or more STA(s) and follow immediately, or after a shortinterval, such as a SIFS, with the transmission of the PCR packets meantfor the STAs. In such embodiments, the multiple WUR packets may be usedto increase the probability of waking up the STA(s). FIG. 13 illustratestransmission of multiple WUR packets. Additionally, in FIG. 14, theconsecutive WUR packets may be separated by some interval, such as SIFS,etc.

In some embodiments, STA1 may transmit multiple WUR packets to a numberof STAs concurrently, either in OFDM fashion or time domain, and followimmediately, possibly with a delay, such as a SIFS interval or wake uptime, with PCR packet transmissions such as a 802.11ax OFDMA and/orMU-MIMO transmission that are meant for the STAs. FIGS. 15 and 16illustrate such embodiments, where FIG. 15 illustrates singletransmission of multiple WUR packets and PCR packets for multiple STAs,while FIG. 16 illustrates consecutive transmission of multi WUR packetsand PCR packets for multiple STAs.

In some embodiments, a procedure for a STA to wake up another STA forUL/DL/Peer2Peer transmissions with a combined WUR and PCR packet and theprocedure for medium access for the STAs to conduct such UL/DL/Peer2Peertransmissions may include the following steps. A STA, e.g., STA1 (whichmay be a non-AP STA or AP), equipped with a WUR transmitter may send aWUF such as a WUReqF to wake up one or more other STAs, e.g., STA2, e.g,when STA1 knows that STA2 is currently in a sleep state. In someembodiments, STA1 includes information in the WUReqF indicating one ormore of the following:

-   -   Purpose of the WUReqF is data transmission (UL/DL/Peer2Peer), or        emergency reporting, status report, etc.    -   Downlink/Uplink/Peer2Peer direction transmission.    -   TX/RX mode: TX/RX mode changes as compared to the last        communications between STA1 and STA2 or the current TX/RX        mode/configurations used by STA1's PCR, such as SU, MU, OFDMA,        MU-MIMO mode, the RU granularity supported by STA1, number of        spatial streams, etc. STA1 may also indicate a preferred        bandwidth, RU or mode. Additionally, or alternatively, STA1 may        indicate the TX/RX mode/configuration that STA2's WUR may adopt        for responding to the WUReqF, such as SU, MU, OFDMA, MU-MIMO        mode, the RU granularity, number of spatial streams, band,        allocated bandwidth/channels/RUs, etc. In addition, STA1 will        specify when the PCR of STA2 should be in RX mode or when STA2's        PCR should be turned on following STA1 WUR transmission. In at        least one embodiment, the WUReqF includes a flag or signal that        may optionally request an acknowledgement. The WUReqF may also        contain a flag that indicates an allowable delay before an        acknowledgement/WURespF is returned. In some embodiments, if        STA1 does not receive an ACK within the desired delay, STA1 may        trigger a retransmission of the WUF. The WURespF may be sent        using code division, sub-channel or random access based methods        detailed below.    -   Additionally, or alternatively, STA1 may indicate the TX/RX        mode/configuration that STA2's PCR may adopt for UL/DL/Peer2Peer        transmissions, such as SU, MU, OFDMA, MU-MIMO mode, the RU        granularity, number of spatial streams, band, allocated        bandwidth/channels/RUs, etc.    -   Buffered traffic priority and indication: the priority and        indication of any buffered traffic for UL transmission.    -   Security Credentials: security credentials that may be        previously established or, for example, in the Security ID        field.    -   Channel quality information: e.g. interference measured at WUR        transmitter and/or transmitted power levels for accelerating and        improving chances of successful reception of any PCR(s)        transmissions back to WUR transmitter.    -   WUR RX: may indicate whether the WUF transmitter has a WUR        receiver. Note that some WUR transmitters may only expect to        receive from WLAN PCRs.

In some embodiments, STA1 sends a unicast WUReqF followed by a unicastPCR packet to STA2, or a WUF broadcast/multicast followed by thebroadcast/multicast PCR packet to one or more STAs including informationindicating one or more of the following:

-   -   Beacon indication; for indicating that the PCR packet includes        updated information of the BSS. Alternatively, or additionally,        the PCR packet may include an AP-CSN number. If a STA detects        that the associated AP has updated the AP-CSN count, the STA may        use its PCR to listen to the next (short) beacon at the next        TBTT or TSBTT.    -   CAG Number: the Common Advertisement Group Number that STA1        currently has.    -   Security Credentials: security credentials that were previously        established, for example, in the Security ID field.

In some embodiments, in response to a STA, e.g., STA2, receiving aWUReqF from a STA, e.g., STA1, STA2 may recognize that STA1 transmissionincludes data transmission (UL/DL/Peer2Peer). In some embodiments, thedata transmission is indicated within the WUReqF, or the STA2 hasdetected that STA1 is its AP or has an established Peer2Peer connection.STA2 may ignore the WUReqF if the security credentials included do notmatch its record or are not correct.

Alternatively, STA2 may respond to the combined transmission of WUReqFand DL data transmissions with a PCR response. Such a response may besent in SU or MU mode, as indicated by the TX/RX mode/configurationhaving been included in WUReqF or any trigger frames contained in thePCR packet. The PCR packet may further include information indicatingone or more of the following:

-   -   TX/RX mode: TX/RX mode changes as compared to the last        communications between STA1 and AP1 or the current TX/RX        mode/configurations used by STA1's PCR, for example, the SU, MU,        OFDMA, MU-MIMO mode, the RU granularity supported by STA2,        number of spatial streams, etc. STA1 may also indicate a        preferred bandwidth, RU or mode.    -   Buffered traffic priority and indication: the priority and        indication of any buffered traffic for UL/Peer2Peer        transmission.    -   ACK/BA for received PCR packets.    -   If STA2 is woken up by a combined transmission of WUR and PCR        packets (which may be indicated by the WUR/PCR packets, for        example, in the preamble, PHY/MAC header or body) and STA2 has        not received a valid PCR packet, it may transmit a packet to        STA2, after some interval, such as a PS-Poll, data, control,        management, extension, NDP frames, to alert STA1 that it is        awake and ready to receive packets.

In some embodiments, STA1 may include a time at which a trigger framemay be transmitted by STA1's PCR in the WUReqF or an additional WUF anda PCR frame scheduling. In alternative embodiments, STA1 may include ascheduling possibly after the frame sent by STA1's PCR. Such ascheduling may indicate a time at which STA2's PCR may starttransmitting/receiving in the WUReqF or another WUF such as a WU Triggerframe.

STA1 may indicate to one or more STAs (e.g., STA2) in the WUReqF whetherSTA2 should transmit or receive at an indicated time. Further, STA1 mayindicate which band, bandwidth, RU, and/or spatial stream STA2 or eachof the STAs should be using for their respective PCR. Further, STA1 mayindicate which TX/RX mode, such as SU, MU, OFDMA, MU-MIMO, STA2 shoulduse. In another example, such specifications may be sent in another WUF,such as WU Trigger frame, that may be transmitted at the time indicatedin the WUReqF or following reception of PCR responses. In someembodiments, PCR SU/MU transmissions are sent by STA1 to one or moreSTAs including STAs indicated by any of the WUFs sent. In someembodiments, a PCR Trigger frame is transmitted to trigger uplinktransmissions by the one or more STAs after a wake-up time of STA1's PCRindicated in the WUReqF or any other WUFs. In yet another embodiment,STA2 transmits a PCR response simply to acknowledge the reception of theWUReqF. Another WUF such as WU Trigger frame or a PRC frame may betransmitted later to provide additional information, such as TX/RX mode,TX/RX band, bandwidth, RU, spatial streams for one or more STAsincluding STA2. Such a frame may be transmitted by the WUR or PCR ofSTA1.

STA2, after receiving such a WUReqF, WUF, or WU Trigger frame, mayswitch its PCR to the correct operating bandwidth, band, and TX/RX modeand may follow the instruction to be in TX or RX mode using its PCR.STA2 may switch the PCR at or before the time indicated in the WUReqFand/or WU Trigger frame and/or WUF using SU or MU mode as indicated tocontinue the UL/DL/Peer2Peer data transmissions following theinstruction of the WUReqF and/or WU Trigger frame and/or WUF and/orPCR's SU/MU transmissions. If a PCR Trigger frame is transmitted bySTA1, then STA2 may follow the instructions to conduct UL/DL datatransmissions process following the instruction of the PCR Triggerframe.

Medium Access and Procedures for WURs and STAs Equipped with WURs

In typical IoT usage scenarios, there may be many sensors and meterslocated within a relatively small area. For such a dense network, it islikely that a number of STAs will attempt to access the medium and wakeup either the same or different APs that are located within the samearea. In exemplary embodiments, a medium access protocol is describedfor providing fair access to these WURs so that the wake-up packets canbe correctly received by their respective receivers. Solutions aredescribed below for providing fair and efficient medium access protocolsfor WURs.

In a dense deployment scenario, multiple STAs may compete and transmituplink wake-up packets. The uplink wake-up packets may be transmittedusing single user transmission mode or multi-user (MU) transmissionmode. In order to allow UL MU wake-up packet transmission, an AP maytransmit a synchronization reference signal, which may be used formultiple STAs to synchronize and begin uplink access. In someembodiments, allowing UL MU wake-up packet transmission includes aperiod or a slotted period for uplink wake-up packet transmission. Insome embodiments, subsequent to transmission of a synchronizationreference signal or other possible DL broadcast frames transmittedthrough WUR, a period is allocated for uplink wake-up packettransmission. The period may be slotted, and one or more uplink accessscheme may be applied.

Code Division Wake-Up Packet Transmissions

In some embodiments, with UL MU wake-up transmission, multiple users areseparated in the time/code/frequency/spatial domain. Further, randomaccess may be applied for UL MU wake-up transmission. In someembodiments, multiple users are separated by orthogonal codes, i.e.,code division wake-up packet transmission. A set of codes having zerocross-correlation property and good auto-correlation property may bepre-defined and stored for all the WUR devices. The code assignment mayfollow one or more methods given below.

In some embodiments, the AP assigns each associated WUR STA a code. Insome embodiments, the code is released and ready for re-assignment whenthe STA de-associates with the AP.

In some embodiments, the AP assigns each associated WUR STA a code whenits primary radio enters a doze state. The code is released and readyfor re-assignment when a primary radio of the STA awakens.

In some embodiments, the STA picks up a code from the code set when itassociated with the AP. Alternatively, the STA may pick up a code fromthe code set when its primary radio enters doze state.

FIG. 4 illustrates an exemplary procedure for code division wake-uptransmission, in accordance with some embodiments. As shown, theprocedure includes allocating the UL wake up period explicitly orimplicitly, assigning code explicitly or implicitly, and applyingrestrictions. A synchronization reference signal 402 is sent by anaccess point, and individual STAs respond during an UL wake-up periodwith UL wake-up packets spread by the appropriate code. The access pointmay respond with an acknowledgement 404.

In some embodiments, an AP acquires the media through contention orscheduling, and the AP transmits the Synchronization Reference Signal(SRS). In some embodiments, the SRS is transmitted periodically.Alternatively, the SRS may be transmitted only if needed.

In some embodiments, an SRS Physical Layer Convergence Protocol (PLCP)Protocol Data Unit (PPDU) format includes a short training field (STF)field for automatic gain control (AGC) and coarse time/frequencysynchronization. The SRS PPDU format further includes a channelestimation field (CEF) field for fine time/frequency synchronization andchannel estimation. In some embodiments, the CEF field is an AP-specificsequence by which the STA identifies the WUR BSS. In alternativeembodiments, the CEF field is scrambled with an AP-specific sequence bywhich the STA may identify the WUR BSS. The SRS PPDU format furtherincludes a SIG field for PHY layer signaling. In some embodiments theSIG field is optional in the case that a limited number of bandwidth,coding and modulation schemes may be used for WUR transmission. In someembodiments the SRS PPDU format further includes a MAC frame or a shortMAC frame. This field may be optional in the case that SIG field may beoverwritten to carry MAC information, or the MAC information may beimplicitly signaled. In some embodiments, a MAC frame is a frame withtraditional 802.11 MAC frame format. Alternatively, the short MAC framemay be a short format of a MAC frame. For example, the TA and RA may beomitted or reduced since the SRS frame is a broadcast frame, and APidentity may be carried by other fields.

In some embodiments information carried by the SRS includes allocationfor a UL wake-up period. In some embodiments of explicit signaling, theallocation indicates the duration of the UL wake-up period, the numberof slots if the slotted period may be utilized, code assignment, and asubset of codes which may be allowed in the UL wake-up period (optionalin the case that only a subset of STAs are allowed to use this ULwake-up period).

In some embodiments the code assignment includes a xIFS duration afterthe reception of the SRS packet, for which the STAs intended for ULtransmission may transmit a UL wake-up packet with codes. Thetransmission may be a CDMA-like UL transmission where the packet may bespread by the code.

In some embodiments, a UL wake-up packet PPDU format includes an STFfield for AGC and coarse time/frequency synchronization. In someembodiments, the STF field is generated based on the user specific code.The UL wake-up packet PPDU format includes a CEF field for finetime/frequency synchronization and channel estimation. In someembodiments, the CEF field is a sequence generated by the user specificcode, by which the AP may identify the STA. In alternative embodiments,the CEF field may be scrambled with the user specific code, by which theAP may identify the STA. The UL wake-up packet PPDU format may alsoinclude a SIG field for PHY layer signaling. This field may be optionalin the case that limited number of bandwidth, coding and modulationschemes may be used for WUR transmission. In some embodiments, the SIGfield is spread by the user-specific code. In some embodiments, the ULwake-up packet PPDU format includes a MAC frame or a short MAC frame.This field may be optional in the case that the SIG field may beoverwritten to carry MAC information or the MAC information may beimplicitly signaled. In some embodiments, a MAC frame may be a framewith traditional 802.11 MAC frame format. In some embodiments, a shortMAC frame may be a short format of a MAC frame. For example, the TA andRA may be omitted or reduced since this is a response frame, and STAidentity may be carried by another field, such as the user specificcode. In some embodiments, the UL wake-up packet PPDU format includesinformation carried by the UL wake-up packet, such as STA identityand/or user specific code confirmation. In some embodiments, the ULwake-up packet PPDU format includes an xIFS duration after the ULwake-up packets, for which the AP may transmit an acknowledgement frameto the multiple STAs.

Sub-Channel Division Wake-Up Packet Transmissions

In some embodiments, multiple users may be separated in the frequencydomain, using channel/sub-channel/resource unit based wake-up packettransmission. A set of channels/sub-channels/resource units may beassigned to a group of associated active WUR devices. Thechannel/sub-channel/resource unit assignment may be signaled in the SRSor previous transmissions. The detailed procedure may be similar to theabove-described code-division wake-up packet transmission. In someembodiments, the SRS frame may be broadcasted, multi-casted, orgroup-casted. FIG. 5 illustrates an exemplary procedure for sub-channelbased wake-up transmission. As shown, the procedure includes allocatingthe UL wake-up period explicitly or implicitly, assigningchannels/sub-channels/resource units explicitly or implicitly, andapplying restrictions. A synchronization reference signal 502 is sent byan access point, and individual STAs respond during an UL wake-up periodwith UL wake-up packets using the appropriate sub-channel. The accesspoint may respond with an acknowledgement 504.

Random Access for Wake-Up Packet Transmissions

In some embodiments, multiple users may compete and access the mediarandomly. Such embodiments may utilize a grid based or slotted ULwake-up period. For example, a M×N grid, having M sub-channels and Ntime slots may be allocated for random access following the SRS. In suchembodiments the minimum value of M and N is 1.

In some embodiments, the random access scheme uses a slotted Aloha-likescheme. In one method, restrictions may be applied to the random access.In such embodiments, the AP assigns each active WUR device a WU ID. Onlya subset of STAs with certain WU ID may use the UL wake-up period forrandom access. The restriction may be signaled in the SRS packet.

Note in all of the examples shown in this embodiment, UL wake-up periodfollows the SRS. In alternative embodiments, the SRS packet may carryinformation to enable a delayed UL wake-up period, where a time offsetmay be indicated for the start of the UL wake-up period. FIG. 6illustrates an exemplary procedure for random access wake-uptransmission, in accordance with some embodiments. As shown, theprocedure includes allocating the UL wake-up period for random accessexplicitly or implicitly, and allocating a number of slots available forrandom access. A synchronization reference signal 602 is sent by anaccess point, and individual STAs respond during an UL wake-up periodwith UL wake-up packets using a slotted random access procedure. Theaccess point may respond with an acknowledgement 604.

Note on Embodiments

Exemplary embodiments are implemented in a STA such as STA 1700 isillustrated in FIG. 17. The access point 1700 includes a primaryconnectivity radio 1702 operative to send and receive data tocommunicate with other devices. The primary connectivity radio 1702 isoperative to enter a sleep state to conserve energy when datacommunications are not required. The access point 1700 further includesa wake up radio 1704 that detects incoming wake up frames anddetermines, using techniques described herein, whether to send a wake upsignal to the primary connectivity radio 1702 in response to a wake upframe. To wake up the primary connectivity radio 1702, the wake up radio1704 is operative to send a wake up signal to the primary connectivityradio 1702.

Although the features and elements are described in the preferredembodiments in particular combinations, each feature or element can beused alone without the other features and elements of the preferredembodiments or in various combinations with or without other featuresand elements of the present invention.

Although the solutions described herein consider 802.11 specificprotocols, it is understood that the solutions described herein are notrestricted to this scenario and are applicable to other wireless systemsas well.

Although SIFS is used to indicate various inter frame spacing in theexamples of the designs and procedures, all other inter frame spacingsuch as RIFS or other agreed time interval could be applied in the samesolutions.

Note that various hardware elements of one or more of the describedembodiments are referred to as “modules” that carry out (i.e., perform,execute, and the like) various functions that are described herein inconnection with the respective modules. As used herein, a moduleincludes hardware (e.g., one or more processors, one or moremicroprocessors, one or more microcontrollers, one or more microchips,one or more application-specific integrated circuits (ASICs), one ormore field programmable gate arrays (FPGAs), one or more memory devices)deemed suitable by those of skill in the relevant art for a givenimplementation. Each described module may also include instructionsexecutable for carrying out the one or more functions described as beingcarried out by the respective module, and it is noted that thoseinstructions could take the form of or include hardware (i.e.,hardwired) instructions, firmware instructions, software instructions,and/or the like, and may be stored in any suitable non-transitorycomputer-readable medium or media, such as commonly referred to as RAM,ROM, etc.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element may be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

What is claimed:
 1. A method performed by a station (STA) equipped witha wake-up radio (WUR) and a primary connectivity radio (PCR), the methodcomprising: while the STA is in a sleep state, receiving on the WUR awake-up frame (WUF) from an access point (AP), where the wake-up packetincludes a WUF purpose field including a purpose indicator identifyingone of a plurality of predetermined WUF purposes; and in response to theWUF, waking up the PCR and operating the PCR to communicate with the APaccording to the purpose identified by the purpose indicator.
 2. Themethod of claim 1, wherein the purpose indicator indicates Listen toBeacon, and wherein operating the PCR comprises receiving the beaconfrom the AP on the PCR.
 3. The method of claim 2, further comprisingreturning the PCR to the sleep state after receiving the beacon.
 4. Themethod of claim 1, wherein the purpose indicator indicates an uplinkdata transmission, and wherein operating the PCR comprises transmittinguplink data from the STA to the AP.
 5. The method of claim 4, whereinthe STA does not send any PS-Poll frame between the waking up of the PCRand the transmission of the uplink data.
 6. The method of claim 1,wherein: the purpose indicator indicates multi-user downlinktransmission; the WUF includes receive parameters; and operating the PCRcomprises using the receive parameters to receive a downlink packetintended for the STA.
 7. The method of claim 6, wherein the receiveparameters include a scheduled receive time for the STA.
 8. The methodof claim 1, wherein the plurality of predetermined WUF purposes includeat least Listen to Beacon, Uplink Data Transmission, Downlink DataTransmission, and Association.
 9. A station (STA) equipped with awake-up radio (WUR) and a primary connectivity radio (PCR), wherein theSTA is configured to perform functions comprising: while the STA is in asleep state, receiving on the WUR a wake-up frame (WUF) from an accesspoint (AP), where the wake-up packet includes a WUF purpose fieldincluding a purpose indicator identifying one of a plurality ofpredetermined WUF purposes; and in response to the WUF, waking up thePCR and operating the PCR to communicate with the AP according to thepurpose identified by the purpose indicator.
 10. The station of claim 9,wherein the purpose indicator indicates Listen to Beacon, and whereinoperating the PCR comprises receiving the beacon from the AP on the PCR.11. The station of claim 10, wherein the station is further operative toreturn the PCR to the sleep state after receiving the beacon.
 12. Thestation of claim 9, wherein the purpose indicator indicates an uplinkdata transmission, and wherein operating the PCR comprises transmittinguplink data from the STA to the AP.
 13. The station of claim 12, whereinthe STA does not send any PS-Poll frame between the waking up of the PCRand the transmission of the uplink data.
 14. The station of claim 9,wherein: the purpose indicator indicates multi-user downlinktransmission; the WUF includes receive parameters; and operating the PCRcomprises using the receive parameters to receive a downlink packetintended for the STA.
 15. The station of claim 9, wherein the pluralityof predetermined WUF purposes include at least Listen to Beacon, UplinkData Transmission, Downlink Data Transmission, and Association.